84593973 2020-03-01
虚拟索引是不占用空间的,可以用来方便的进行sql 查询的性能评估,帮助我们了解查询优化的效果
hypopg 是一个pg 扩展,提供了比较方便的函数,我们可以用来评估查询,以下是pgspider 集成hypopg
的一个学习
FROM dalongrong/pgspider:base as build WORKDIR /app RUN apt-get update && apt-get install -y automake autoconf libtool pkg-config libssl-dev RUN git clone https://github.com/HypoPG/hypopg.git /app/postgresql-11.6/contrib/hypopg RUN git clone https://github.com/powa-team/pg_qualstats.git /app/postgresql-11.6/contrib/pg_qualstats RUN cd /app/postgresql-11.6/contrib/hypopg && make && make install RUN cd /app/postgresql-11.6/contrib/pg_qualstats && make && make install ? FROM debian:stretch-slim ENV GOSU_VERSION 1.11 RUN apt-get update && apt-get install -y wget libreadline-dev # explicitly set user/group IDs RUN set -eux; \ groupadd -r postgres --gid=999; \ # https://salsa.debian.org/postgresql/postgresql-common/blob/997d842ee744687d99a2b2d95c1083a2615c79e8/debian/postgresql-common.postinst#L32-35 useradd -r -g postgres --uid=999 --home-dir=/var/lib/postgresql --shell=/bin/bash postgres; \ # also create the postgres user‘s home directory with appropriate permissions # see https://github.com/docker-library/postgres/issues/274 mkdir -p /var/lib/postgresql; \ chown -R postgres:postgres /var/lib/postgresql ? RUN wget -O /usr/local/bin/gosu "https://github.com/tianon/gosu/releases/download/$GOSU_VERSION/gosu-$(dpkg --print-architecture)" \ && chmod +x /usr/local/bin/gosu \ && gosu nobody true # make the "en_US.UTF-8" locale so postgres will be utf-8 enabled by default RUN set -eux; \ if [ -f /etc/dpkg/dpkg.cfg.d/docker ]; then \ # if this file exists, we‘re likely in "debian:xxx-slim", and locales are thus being excluded so we need to remove that exclusion (since we need locales) grep -q ‘/usr/share/locale‘ /etc/dpkg/dpkg.cfg.d/docker; \ sed -ri ‘/\/usr\/share\/locale/d‘ /etc/dpkg/dpkg.cfg.d/docker; \ ! grep -q ‘/usr/share/locale‘ /etc/dpkg/dpkg.cfg.d/docker; \ fi; \ apt-get update; apt-get install -y locales; rm -rf /var/lib/apt/lists/*; \ localedef -i en_US -c -f UTF-8 -A /usr/share/locale/locale.alias en_US.UTF-8 ENV LANG en_US.utf8 ? # install "nss_wrapper" in case we need to fake "/etc/passwd" and "/etc/group" (especially for OpenShift) # https://github.com/docker-library/postgres/issues/359 # https://cwrap.org/nss_wrapper.html RUN set -eux; \ apt-get update; \ apt-get install -y --no-install-recommends libnss-wrapper; \ rm -rf /var/lib/apt/lists/* ? RUN mkdir /docker-entrypoint-initdb.d COPY --from=build /usr/local/pgspider /usr/local/pgspider RUN sed -ri "s!^#?(listen_addresses)\s*=\s*\S+.*!\1 = ‘*‘!" /usr/local/pgspider/share/postgresql/postgresql.conf.sample; \ grep -F "listen_addresses = ‘*‘" /usr/local/pgspider/share/postgresql/postgresql.conf.sample RUN echo "shared_preload_libraries = ‘pg_qualstats‘" >> /usr/local/pgspider/share/postgresql/postgresql.conf.sample RUN mkdir -p /var/run/postgresql && chown -R postgres:postgres /var/run/postgresql && chmod 2777 /var/run/postgresql ENV PATH $PATH:/usr/local/pgspider/bin ENV PGDATA /var/lib/postgresql/data RUN mkdir -p "$PGDATA" && chown -R postgres:postgres "$PGDATA" && chmod 777 "$PGDATA" VOLUME /var/lib/postgresql/data COPY docker-entrypoint.sh /usr/local/bin/ RUN ln -s usr/local/bin/docker-entrypoint.sh / # backwards compat ENTRYPOINT ["docker-entrypoint.sh"] ? EXPOSE 5432 CMD ["postgres"]
version: "3" services: pg: image: dalongrong/pgspider:hypopg-pg_qualstats ports: - "5432:5432" environment: - "POSTGRES_PASSWORD=dalong"
docker-compose up -d
CREATE EXTENSION hypopg;
CREATE TABLE hypo AS SELECT id, ‘line ‘ || id AS val FROM generate_series(1,10000) id;
EXPLAIN SELECT * FROM hypo WHERE id = 1;
SELECT * FROM hypopg_create_index(‘CREATE INDEX ON hypo (id)‘);
SELECT * FROM hypopg_list_indexes();
EXPLAIN SELECT * FROM hypo WHERE id = 1;
效果
EXPLAIN ANALYZE SELECT * FROM hypo WHERE id = 1;
使用hypopg 扩展你的好处是我们不需要花费空间以及多大的时间,就可以通过慢慢试错同时不影响环境的情况下,进行
sql 的优化调整,是一个很不错的扩展工具
https://github.com/HypoPG/hypopg
https://rjuju.github.io/postgresql/2015/07/02/how-about-hypothetical-indexes.html
https://hypopg.readthedocs.io/en/latest/
https://github.com/rongfengliang/pgspider-docker/blob/master/Dockerfile-hypopg-pg_qualstats